Communication between and among people is seldom limited to one subject or topic. Typically, communications may begin with greetings and polite exchanges, then progress to a specific topic in which there may be an exchange of dialog. In some instances, the communication will change topics and continue with additional dialog, and the topic change may repeat itself during the communication.
Determining when a change of topic occurs would be useful to provide information relevant to the topic of the communication that the participants might find useful. Relevant information may include factual content related to the topic, links to content providing information, links or email addresses to “experts”, or even advertisements of providers of services or products related to the topic.